Table 1.
Elemental compositions, shapes, sizes, locations and abundance of crystals formed in phyllodes and branchlets of Acacia robeorum
| Elemental composition (type) | Shape | Size | Location | Abundance |
|---|---|---|---|---|
| Ca C O (1) | Prisms (Figs 2A, B, 3A, B) | 5–10 µm side length | Phloem fibre cells and cells associated with phloem fibre cells in phyllodes; pith, pith ray cells, xylem fibre cells and cortical cells associated with phloem fibre cells in branchlets | Present in >50 % of the cells, only one per cell |
| Ca C O (1) | Raphide bundles (Fig. 2C, D) | 25–29·5 µm wide, 64·5–181·5 µm long | Mesophyll and parenchyma cells in phyllodes | Varied greatly in different parts of a phyllode, ≥1 per cell |
| Ca C O (1) | Raphide clusters on styloids (Fig. 2E, G, H) | Not measured | Parenchyma cells in phyllodes | Varied greatly in different parts of a phyllode, only one per cell |
| Ca C O (1) | Solitary raphides (Fig. 3C) | Not measured | Pith, pith ray cells, xylem fibre cells and cortical cells in branchlets | Present in <50 % of the cells, ≥1 per cell |
| Ca C O (1) | Solitary styloids (Figs 2F, 3D) | 6–112·5 µm long | Mesophyll and parenchyma cells in phyllodes; pith, pith ray cells, xylem fibre cells and cortical cells in branchlets | Present in <50 % of the cells, only one per cell |
| Ca C O (1) | Styloid druses (Fig. 2I) | 12–25 µm diameter | Mesophyll and parenchyma cells in phyllodes; cortical cells in branchlets | Present in <50 % of the cells, ≥1 per cell |
| Ca C O (1) | Bundles or clusters of crystals which are intermediate forms of styloids and raphides (Figs 2J, 3E, F) | Not measured | Mesophyll and parenchyma cells in phyllodes; pith, pith ray cells, xylem fibre cells and cortical cells in branchlets | Sporadic |
| Ca S C O (2) | Platy aggregation clusters (Fig. 2K, L) | 10–25 µm wide, 20–100 µm long | Mesophyll cells in phyllodes | Present in >50 % of the cells, only one per cell |
| Ca S C O (2) | Tabular crystal druses (Fig. 2M) | 20 µm diameter | Parenchyma cells in phyllodes | Sporadic, only one per cell |
| Ca S C O (2) | Blocky and tabular crystal druses (Fig. 2N) | 2·5–50 µm diameter | Mesophyll and parenchyma cells in phyllodes | Present in >50 % of the cells, ≥1 per cell |
| Ca S C O (2) | Platy crystal druses (Fig. 2O) | 12–16·5 µm diameter | Parenchyma cells in phyllodes | Sporadic, >1 per cell |
| Ca S C O (2) | Crystal sand (Fig. 2P) | Not measured | Mesophyll and parenchyma cells in phyllodes; pith in branchlets | Present in >50 % of the cells, numerous per cell |
| Ca S C O (2) | Bladed aggregation clusters (Fig. 3G, H) | 3–4 µm wide, 4–5 µm long | Xylem fibre cells | Present in >50 % of the cells, ≥1 per cell |
| Ca S C O (2) | Bladed aggregation druses (not shown in figures) | 2–5 µm diameter | Pith and cortical cells in branchlets | Sporadic, >1 per cell |
| Ca K S C O (2) | Tetrahedral crystal druses (Fig. 2Q) | 16–20 µm diameter | Mesophyll and parenchyma cells in phyllodes | Sporadic, only one per cell |
| Ca Mg K Si S C O (3) | Spheres (Fig. 2R) | 3·5–16 µm diameter | Mesophyll and parenchyma cells in phyllodes | Present in almost every cell, ≥ 1 per cell |
Data are summarized from SEM images of five cross-sections of a phyllode and three cross-sections of a branchlet, at least three EDS spectra for each type of crystal, together with optical microscope images of six cross-sections of a phyllode.